System for detecting air

ABSTRACT

A dual port syringe has an upper port for connection to a fluid reservoir and a lower port for delivery of the medical fluid under pressure to a patient. A first valve is connected between the fluid reservoir and the upper port, and second valve is connected between the lower port and the patient. During a fill operation, a piston is moved within the syringe to drawn fluid from the reservoir into the syringe through the upper port. During injection operation, the piston moves in an opposite direction to force fluid out of the syringe through the lower port.

This application is a divisional of U.S. application Ser. No.10/853,893, filed May 26, 2004, now U.S. Pat. No. 6,945,959 which is acontinuation of U.S. application Ser. No. 10/174,356, filed Jun. 17,2002, now U.S. Pat. No. 6,746,427, which is a continuation of U.S.application Ser. No. 09/575,406, filed May 22, 2000, now U.S. Pat. No.6,447,481, which is a continuation of U.S. application Ser. No.08/957,228, filed Oct. 24, 1997, now U.S. Pat. No. 6,099,502, which is acontinuation-in-part of U.S. application Ser. No. 08/946,667, filed Oct.7, 1997, now U.S. Pat. No. 5,882,343, which is a continuation of U.S.application Ser. No. 08/426,149, filed Apr. 20, 1995, now abandoned, allof which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

This invention relates to angiography and more specifically, theinjector used to inject a medical fluid such as radiographic contrastmaterial into living organisms.

One of the major systems in the human body is the circulatory system.The major components of the circulatory system are the heart, bloodvessels, and the blood, all of which are vital to the transportation ofmaterials between the external environment and the different cells andtissues of the human body.

The blood vessels are the network of passageways through which the bloodtravels in the human body. Specifically, arteries carry the oxygenatedblood away from the left ventricle of the heart. These arteries arealigned in progressively decreasing diameter and pressure capabilityfrom the aorta, which carries the blood immediately out of the heart toother major arteries, to smaller arteries, to arterioles, and finally totiny capillaries, which feed the cells and tissues of the human body.Similarly, veins carry the oxygen-depleted blood back to the rightatrium of the heart using a progressively increasing diameter network ofvenules and veins.

If the heart chambers, valves, arteries, veins or other capillariesconnected thereto are either abnormal (such as from a birth defect),restricted (such as from atherosclerotic plaque buildup), ordeteriorating (such as from aneurysm formation), then a physician mayneed to examine the heart and connected network of vessels. Thephysician may also need to correct any problems encountered during theexamination with a catheter or similar medical instrument.

Angiography is a procedure used in the detection and treatment ofabnormalities or restrictions in blood vessels. During angiography, aradiographic image of a vascular structure is obtained by injectingradiographic contrast material through a catheter into a vein or artery.The vascular structures fluidly connected with the vein or artery inwhich the injection occurred are filled with contrast material. X-raysare passed through the region of the body in which the contrast,material was injected. The X-rays are absorbed by the contrast material,causing a radiographic outline or image of the blood vessel containingthe contrast material. The x-ray images of the blood vessels filled withcontrast material are usually recorded onto film or videotape and aredisplayed on a fluoroscope monitor.

Angiography gives the doctor an image of the vascular structures inquestion. This image may be used solely for diagnostic purposes, or theimage may be used during a procedure such as angioplasty where a balloonis inserted into the vascular system and inflated to open a stenosiscaused by atherosclerotic plaque buildup.

Currently, during angiography, after a physician places a catheter intoa vein or artery (by direct insertion into the vessel or through a skinpuncture site), the angiographic catheter is connected to either amanual or an automatic contrast injection mechanism.

A simple manual contrast injection mechanism typically has a syringe anda catheter connection. The syringe includes a chamber with a plungertherein. Radiographic contrast material is suctioned into the chamber.Any air is removed by actuating the plunger while the catheterconnection is facing upward so that any air, which floats on theradiographic contrast material, is ejected from the chamber into theair. The catheter connection is then attached to a catheter that ispositioned in a vein or artery in the patient.

The plunger is manually actuated to eject the radiographic contrastmaterial from the chamber, through the catheter, and into a vein orartery. The user of the manual contrast injection mechanism may adjustthe rate and volume of injection by altering the manual actuation forceapplied to the plunger.

Often, more than one type of fluid injection is desired, such as asaline flush followed by the radiographic contrast material. One of themost common manual injection mechanisms used today includes a valvemechanism which controls which of the fluids will flow into the valvingmechanism and out to the catheter within the patient. The valvemechanism contains a plurality of manual valves that the user operatesmanually to open and close that particular fluid channel. When the usersuctions or injects contrast fluid into the chamber, the fluid is pulledfrom the valve mechanism via the open valves. By changing the valvepositions, another fluid may be injected.

These manual injection mechanisms are typically hand actuated. Thisallows user control over the quantity and pressure of the injection.However, all of the manual systems are only capable of injecting theradiographic contrast material at maximum pressure that can be appliedby the human hand (i.e., 150 p.s.i). Also, the quantity of radiographiccontrast material is typically limited to a maximum of about 12 cc.Finally, there are no safety limits on these manual contrast injectionmechanisms which act to restrict or stop injections that are outside ofreasonable parameters (such as rate or pressure) and no active sensorsto detect air bubbles or other hazards.

Currently used motorized injection devices consist of a syringeconnected to a linear actuator. The linear actuator is connected to amotor, which is controlled electronically. The operator enters into theelectronic control a fixed volume of contrast material to be injected ata fixed rate of injection. The fixed rate of injection consists of aspecified initial rate of flow increase and a final rate of injectionuntil the entire volume of contrast material is injected. There is nointeractive control between the operator and machine, except to start orstop the injection. Any change in flow rate must occur by stopping themachine and resetting the parameters.

The lack of ability to vary the rate of injection during the injectionresults in suboptimal quality of angiographic studies. This is becausethe optimal flow rate of injections varies considerably betweenpatients. In the cardiovascular system, the rate and volume of contrastinjection is dependent on the size of and blood flow rate within thechamber or blood vessel being injected. In many or most cases, theseparameters are not known precisely. Moreover, the optimal rate ofinjection can change rapidly, as the patient's condition changes inresponse to drugs, illness, or normal physiology. Consequently, theinitial injection of contrast material may be insufficient in flow rateto outline the structure on x-ray imaging, necessitating anotherinjection. Conversely, an excessive flow rate might injure the chamberor blood vessel being injected, cause the catheter to be displaced (fromthe jet of contrast material exiting the catheter tip), or lead to toxiceffects from contrast overdose (such as abnormal heart rhythm).

At present, the operator can choose between two systems for injectingcontrast material: a manual injection system which allows for avariable, operator interactive flow rate of limited flow rate and apreprogrammed motorized system without operator interactive feedback(other than the operator can start/stop the procedure).

SUMMARY OF THE INVENTION OF APPLICATION SER. NO. 08/426,149

The invention described in Ser. No. 08/426,149 is a dual port syringeused to deliver medical fluids such as angiographic radiographiccontrast material to a patient. The dual port syringe includes a syringebody, a piston which is reciprocally movable in the syringe body, andupper and lower parts.

The upper port is connected to a fluid reservoir so that medical fluidis drawn from the fluid reservoir through the upper port into thesyringe body when the piston moves in a rearward direction. The lowerport is connected to a device, such as a catheter, through which themedical fluid is delivered under pressure to the patient. When thepiston moves in a forward direction, medical fluid is delivered underpressure out of the syringe body through the lower port.

In preferred embodiments, the first valve is connected between the fluidreservoir and the upper port, and a second valve is connected betweenthe lower port and patient. The first valve permits flow of fluid fromthe fluid reservoir to the upper port when the piston moves rearwardlyand air to be expelled when the piston moves forwardly. The second valvepermits flow of material out of the lower port when the piston moves ina forward direction.

SUMMARY OF THE PRESENT INVENTION

The present invention comprises a syringe for use in a angiographicinjector of a type having a syringe holder. The syringe includes asyringe body having a distal end and a proximal end. The syringe bodydefines a pumping chamber and an inlet port. A syringe end wall islocated at the distal end of the syringe body and has a flat face formating engagement with the syringe holder. The end wall defines anoutlet port. A syringe plunger is located in the pumping chamber and isadapted for reciprocal motion between a position proximate to theproximal end and the distal end.

Preferably, the syringe end wall defines an interior portion and anexterior portion. The exterior portion defines the flat face. Inpreferred embodiments, the exterior portion is reinforced with aplurality of ribs. The ribs each have end portions terminating in aplane transverse to a longitudinal axis of the syringe body. The endportions of the ribs define the flat face. Preferably, the interiorportion defines a cone-shaped surface.

In one preferred arrangement, the syringe body defines a top portion.The inlet port is located in the top portion.

Preferably, the end wall defines a first portion and a second portion.The first portion is adjacent to the top portion of the syringe body,and the second portion is adjacent to an end of the end wall opposite ofthe first portion. The outlet port is preferably located in the secondportion of the end wall.

Preferably, a valve arrangement is constructed and arranged to preventliquid from flowing out of the pumping chamber through the inlet portwhen the plunger moves from the proximal end to the distal end.

In another aspect, the invention is directed to an injection systemcomprising a syringe and a syringe holder arrangement. The syringeincludes a barrel defining a pumping chamber, a longitudinal axis, andat least one port for providing fluid flow communication with thepumping chamber. The barrel has a distal end and a proximal end. Thedistal end includes a flat wall section normal to the centrallongitudinal axis. The syringe includes a plunger constructed andarranged within the pumping chamber for reciprocal motion between aposition adjacent to the proximal end and the distal end. The syringeholder arrangement includes a mounting chamber body and door member. Themounting chamber body is constructed and arranged to hold the syringe,and it includes a loading end for receipt of the syringe. The doormember is movable relative to the body to allow for selective openingand closing of the loading end of the mounting chamber body. The doormember defines a flat, planar surface for abutting engagement with theflat wall section of the syringe.

Preferably, the syringe includes an inlet port and an outlet port. Theoutlet port is preferably defined by the flat wall section. The syringeincludes an inlet port housing surrounding the inlet port, and an outletport housing surrounding the outlet port. The outlet port housingprojects from the flat wall section.

Preferably, the door member defines a slot for slidable communicationwith the outlet port housing. That is, as the door member rotates into aclosed position, the outlet port housing slides in the slot.

In one preferred embodiment, the syringe holder arrangement furtherincludes a pressure containment sleeve selectively mounted within themounting chamber body for slidable receipt of the syringe. The pressurecontainment sleeve defines open first and second, opposite ends. Thefirst end is adjacent to the loading end of the mounting chamber body.The door member is selectively movable to open and close the first end.

Preferably, the pressure containment sleeve defines an open channel forslidable communication with the inlet port housing.

In preferred arrangements, the syringe holder arrangement furtherincludes a plate mounted in covering relation to the second end of thepressure containment sleeve. The plate defines an aperture for allowingmanipulation of the syringe plunger, when the syringe is positioned inthe pressure containment sleeve. Preferably, the syringe holderarrangement further includes a bottle-holder assembly constructed andarranged to mount a bottle in fluid flow communication with the inletport housing.

In another aspect, the invention is directed to a method for mounting asyringe. The method comprises a step of first, positioning a syringethrough a front aperture in a syringe holder arrangement. After the stepof positioning a syringe, the method includes pivoting a door of thesyringe holder arrangement to close the front aperture and abut a frontface of the syringe.

Preferably, the step of positioning a syringe includes providing asyringe having a first end at the syringe front face and defining afluid port, and a second end slidably receiving a plunger. The step ofpositioning includes orienting the syringe through the front aperturesuch that the second end passes through the front aperture followed bythe first end.

In one preferred method, the step of positioning a syringe includesinserting the syringe into an interior of a pressure containment sleeve.

Preferably, the front face of the syringe is planar with an outlet porthousing extending therefrom surrounding the fluid port, and the doorincludes a planar surface. The step of pivoting a door includes slidingthe planar surface of the door relative to the planar, front face of thesyringe.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a preferred embodiment of theangiographic injector system of the present invention.

FIGS. 2A–2G are diagrams illustrating operations of the system of FIG.1.

FIG. 3 is an electrical block diagram of the control system of theinjector system of FIG. 1.

FIG. 4 illustrates front panel controls and displays of a preferredembodiment of the injector system of the present invention.

FIGS. 5A and 5B are side and partial top perspective views of the remotecontrol of the system of FIG. 1.

FIG. 6 is a perspective view of a foot operated remote control.

FIGS. 7A–7D illustrate the operation of the inlet check valve andmanifold during contrast fill, air purge and patient inject operations.

FIGS. 8A–8C illustrate operation of the inlet check valve in greaterdetail.

FIG. 9 shows a conventional syringe body adapted for dual port

FIG. 10 is a perspective view of an adapter insert used in the dual portsyringe of FIG. 9.

FIGS. 11A–11B are top and side views of the adapter insert of FIG. 10.

FIG. 12 is a perspective view of one embodiment of a syringe usable inthe angiographic injector system, according to the present invention.

FIG. 13 is a bottom plan view of the syringe depicted in FIG. 12.

FIG. 14 is a top plan view of the syringe depicted in FIG. 12.

FIG. 15 is a side elevational view of the syringe depicted in FIG. 12.

FIG. 16 is a front side elevational, view of the syringe depicted inFIG. 12.

FIG. 17 is a rear side elevational view of the syringe depicted in FIG.12, and without the plunger therein.

FIG. 18 is a perspective view of one embodiment of a syringe holderarrangement, according to the present invention

FIG. 19 is a perspective view of the syringe holder arrangement depictedin FIG. 18, and holding a syringe and a bottle of fluid.

FIG. 20 is an exploded, perspective view of a subassembly of the syringeholder arrangement depicted in FIG. 18.

FIG. 21 is a rear side elevational view of the syringe depicted in FIG.12, and analogous to FIG. 17, but with the plunger therein.

FIG. 22 is a schematic, side elevational view of an air column detectorand tubing, in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A. Application Ser. No. 08/426,149

FIG. 1 shows angiographic injector system 10 for injecting radiographiccontrast material into a blood vessel under interactive physiciancontrol. System 10 includes main console 12, hand held remote control14, syringe holder 16, syringe body 18, syringe plunger 20, radiographicmaterial reservoir (bottle) 22, one-way valve 24, manifold 26, highpressure tube 28, catheter 30, patient medication port 32, three-waystop-cock 34, T-connector 36, pressure transducer 38, stop-cock 40,tubing 42, peristaltic pump 44, saline check valve 46, waste check valve48, saline bag 50, waste bag 52, and bag support rack 54.

Console 12 houses the electrical controls for system 10, together withthe motors which drive piston 20 and peristaltic pump 44. On the frontsurface of console 12, user interface 54 provides control switches 56and display 58 through which the user may enter control settings andmonitor the operational state of system 10.

Remote control 14 is connected to console 12 by cable 60 (although inother embodiments remote control 14 may be connected by a wirelessconnection such as an RF, infrared optic, or ultrasonic link). Remotecontrol 14 is, in the embodiment shown in FIG. 1, a hand-held controlwhich includes reset and saline push button switches 62 and 64,respectively, and flow rate control lever or trigger 66. By squeezingtrigger 66, the user can provide a command signal to console 12 toprovide a continuously variable injection rate.

Syringe holder 16 projects from the left hand side of console 12.Syringe holder 16 is preferably a clear material, and includes a halfcylindrical back shell 68, a half cylindrical front door 70 (which isshown in open position in FIG. 1), and reservoir holder 72.

Syringe 18 is a transparent or translucent plastic cylinder having itsopen end 74 connected to console 12. Closed end 76 of syringe 18contains two ports, upper port 78 and lower port 80.

Plunger 20 is movable within syringe body 18. Plunger 20 is connectedto, and driven by a motor located within console 12.

Radiographic contrast material reservoir 22 is connected through one-waycheck valve 24 to upper port 78. Radiographic contrast material is drawnfrom reservoir 22 through check valve 24 and upper port 78 into thepumping chamber defined by syringe body 18 and plunger 20. Check valve24 is preferably a weighted one-way valve which permits air to flow fromsyringe body 18 back into reservoir 22, but will not permit radiographiccontrast material to flow from syringe body 18 to reservoir 22. Thispermits automatic purging of air from the system, as will be describedin more detail later.

Lower port 80 of syringe body 18 is connected to manifold 26. Manifold26 includes a spring biased spool valve which normally connectstransducer/saline port 82 and patient port 84. When radiographiccontrast material is to be injected, the pressure of the radiographicmaterial causes the spool valve to change states so that lower port 80is connected to patient port 84.

High pressure tube 28 is a flexible tube which connects patient port 84to catheter 30. Three-way stop-cock 34 is located at the distal end oftube 28. Rotatable luer lock connector 86 is connected to stop-cock 34and mates with luer connector 88 at the proximal end of catheter 30.Stopcock 34 either blocks flow between tube 28 and catheter 30, permitsflow, or connects medication port 32 to catheter 30.

In addition to injecting radiographic material into a patient throughcatheter 30, system 10 also permits other related functions to beperformed. A device for delivering the patient medication (not shown inFIG. 1) may be connected to medication port 32 when medication is to bedelivered through catheter 30 to the patient.

When catheter 30 is in place in the patient, and an injection ofradiographic contrast material is not taking place, pressure transducer38 monitors the blood pressure through the column of fluid which extendsfrom catheter 30, tube 28, patient port 84, manifold 26,transducer/saline port 82, tubing 90, T-connector 36, and tubing 92.Transducer 38 has an associated stop-cock 40 which allows transducer 38to be exposed to atmospheric pressure during calibration and also allowsfor removal/expulsion of trapped air so the dome chamber of transducer38 can be flushed with saline.

Peristaltic pump 44 supplies saline solution from bag 50 through salinecheck valve 46, tubing 42, T-connector 36 and tubing 90 to saline port82. When peristaltic pump 44 is operating to supply saline solution, thesaline solution is supplied through manifold 26 to patient port 84 andthen through tube 28 to catheter 30.

Peristaltic pump 44 also operates in an opposite direction to draw fluidfrom catheter 30 and through tube 28, manifold 26, tubing 90,T-connector 36 and tubing 42 to waste check valve 48 and then into wastecollection bag 52.

In a preferred embodiment of the invention, syringe body 18, manifold26, tube 28, catheter 30, T-connector 36, tubing 42, check valves 46 and48, bags 50 and 52, and tubing 90 and 92 are all disposable items. Theymust be installed in system 10 each time an angiography procedure is tobe performed with a new patient. Once system 10 is set up with all thedisposable items installed, door 70 is closed, and syringe body 18filled with contrast material and purged of air, the user (typically aphysician) enters into system 10 the safety parameters that will applyto the injection of radiographic contrast material. These safetyparameters typically include the maximum amount of radiographic contrastmaterial to be injected during any one injection, the maximum flow rateof the injection, the maximum pressure developed within syringe body 18,and the maximum rise time or acceleration of the injection. To actuatean injection of contrast material, the user operates remote control 14by squeezing trigger 66. Within the preset safety parameters, system 10causes the flow rate of the injection to increase as the force ordistance of travel of trigger 66 is increased.

Typically, the user will meter the amount and rate of contrast materialinjected based upon continuous observation of the contrast outflow intothe structure being injected using fluoroscopy or other imaging methods.System 10 allows the user to tailor the contrast injections to the needsof the patient, thereby maximizing the quality of the procedure,increasing the safety, and reducing the amount of contrast materialrequired to perform the fluoroscopic examination.

FIGS. 2A–2G are diagrams illustrating fluid flow paths during sevendifferent operations of system 10. Those operations are contrast fill(FIG. 2A), air purge (FIG. 2B), patient inject (FIG. 2C), patientpressure (FIG. 2D), saline flush (FIG. 2E), aspirate waste (FIG. 2F),and medicate patient (FIG. 2G).

The contrast fill operation illustrated in FIG. 2A involves the fillingof syringe body 18 with radiographic contrast material from reservoir(contrast media supply) 22. The contrast fill operation is performedduring initial set up of system 10, and may be repeated during operationof system 10 whenever syringe body 18 is running low on radiographiccontrast material.

During initial set up of system 10, plunger 20 is initially driven toits furthest forward position adjacent closed end 76 of syringe body 18.This will expel to the atmosphere the majority of the air which islocated within syringe body 18.

Plunger 20 is then retracted, which creates a vacuum within syringe body18 which draws contrast material from reservoir 22 through check valve24 into syringe body 18 through upper port 78.

The Contrast Fill operation typically, will result in some air beingdrawn into or remaining within syringe body 18. It is important, ofcourse, to prevent air from being injected into the patient throughcatheter 30. That is the purpose of the Air Purge operation shown inFIG. 2B. Also, the location of two ports at different elevations allowsfor a greater amount of safety in preventing air bubbles in theinjection.

During the Air Purge operation, plunger 20 travels forward to expeltrapped air within syringe body 18. The air, being lighter than thecontrast material, gathers near the top of syringe body 18. As plunger20 moves forward, the air is expelled from syringe body 18 through upperport 78 and one-way valve 24. In the embodiment illustrated in FIG. 2B,one-way valve 24 is a weighted one-way valve which allows flow ofradiographic contrast material from reservoir 22 to upper port 78, butwill not allow radiographic contrast material to flow in the oppositedirection from upper port 78 to reservoir 22. Valve 24 will, however,allow air to flow from port 78 to reservoir 22. As soon as radiographiccontrast material begins flowing out of syringe body 18 through upperport 78 to valve 24, valve 24 closes to prevent any further flow towardreservoir 22.

Valve 24 can also, in alternative embodiments, can be a solenoidactuated or motor driven valve operated under control of the electriccircuitry within console 12. In either case, valve 24 is capable towithstanding the relatively high pressures to which it will be subjectedduring the inject operation. Preferably, valve 24 is capable ofwithstanding static fluid pressures up to about 1200 p.s.i.

FIG. 2C illustrates the Patient Inject operation. Plunger 20 travelsforward under the interactive control of the user, who is controllingtrigger 66 of remote control 14. The movement of plunger 20 createshydraulic pressure to force contrast material out of syringe body 18through lower port 80 and through manifold 26 and high pressure tube 28into catheter 30. As shown in FIG. 2C, syringe lower port 80 and patientport 84 are connected for fluid flow during the patient injectoperation.

Manifold 26 contains a valve which controls the routing of fluidconnections between patient port 84 and either syringe bottom port 80 ortransducer/saline port 82. In one embodiment of the invention, manifold26 includes a spool valve which is spring biased so that patient port 84is normally connected to transducer/saline port 82 (as illustrated inFIGS. 2A and 2B). When the pressure at syringe bottom port 80 buildswith the movement of plunger 20 forward, the bias force against thespool valve is overcome so that syringe bottom port 80 is connected topatient port 84, and transducer/saline port 82 is disconnected the valvewithin manifold 26 protects pressure transducer 38 from being exposed tothe high pressure generated by the patient inject operation.

The spool valve opens automatically during the patient inject operationin response to increase pressure exerted on it from the syringe lowerport 80. The spool valve closes and returns to its original positionallowing for connection of patient port 84 to transducer 38 when aslight vacuum is applied by retraction of plunger 20 at the end of eachPatient Inject operation.

In an alternative embodiment, the valve within manifold 26 is anelectromechanical or motor driven valve which is actuated at appropriatetimes to connect either syringe lower port 80 or transducer/saline port82 to patient port 84. The actuator mechanism is controlled by console12. Once again in this alternative embodiment, the valve protectspressure transducer 38 from being exposed to high pressure.

FIG. 2D illustrates the Patient Pressure operation. System 10 allows forreading of the patient's blood pressure, which is monitored throughcatheter 30. Patient blood pressure can be monitored through the use ofpressure transducer 38 at any time except during the patient inject,saline flush, and waste aspirate operations. The pressure reading beingproduced by pressure transducer 38 may be normalized by manually openingstop-cock 40 and closing stopcock 34 to expose pressure transducer 38 toatmospheric pressure.

During the Saline Flush operation illustrated in FIG. 2E, salinesolution is used to flush all of the internal lines, pressure transducerchamber 38, tube 28, and catheter 30. As shown in FIG. 2E, peristalticpump 44 is operating in a direction which causes saline solution to bedrawn from bag 50 through check valve 46 and through tubing 42 to salineport 82. Manifold 26 connects saline port 82 to patient port 84 so thatsaline solution is pumped out of patient port 84 and through tube 28 andcatheter 30.

During the Aspirate Waste operation, patient port 84 is again connectedto saline port 82. During this operation, peristaltic pump 44 isoperating in the opposite direction from its rotation during the salineflush operation. As a result, patient fluids are aspirated from patientport 84 to saline port 82 and then through tubing 42 and check valve 48into waste collection bag 52. Peristaltic pump 44 acts as a valvepinching/occluding tubing 42 and preventing back flow to/from saline andwaste containers 50 and 52 in conjunction with check valves 46 and 48.

With catheter 30 in place within the patient, it may be desirable tosupply patient medication. System 10 allows for that option by providingpatient medication port 32. As shown in FIG. 2G, when stop-cock 34 isopen, a medication source connected to port 32 will be connected topatient port 84, and thereby to catheter 30. During the medicate patientoperation, peristaltic pump 44 and plunger 20 are not moving.

FIG. 3 is an electrical block diagram of the control system whichcontrols the operation of angiographic injector system 10. Theelectrical control system includes digital computer 100, which receivesinput signals from remote control 14 and front panel controls 56 throughinterface 102, and provides signals to display 58 to display operationdata, alerts, status information and operator prompts.

Computer 100 controls the motion of plunger 20 through a motor drivecircuit which includes motor 104, motor amplifier 106, tachometer 108,potentiometer 110, a rectifier 112, pressure sensing load cell 114, andA/D converter 160.

Motor amplifier 106 provides a drive signal to motor 104 in response toControl Voltage, Fwd/Rev, and/Brake signals from computer 100 and aspeed feedback signal from tachometer 108 through rectifier 112. Theoutputs of tachometer 108 and potentiometer 110 are supplied to computer100 through A/D converter 116 as Speed Monitor and Position Monitorsignals. These allow computer 100 to check motor speed, motor direction,and position (volume is a calculated value).

Pressure sensor 114 senses motor current or plunger force in order tomeasure the pressure being applied to the radiographic contrast materialwithin syringe body 18. This Pressure Monitor Signal is supplied throughAID converter 116 and interface 102 to computer 100.

Peristaltic pump 44 is driven under the control of computer 100 throughpump motor 120, motor driver 122 and optical encoder 124. Computer 100provides Saline (Forward) and Waste (Reverse) drive signals to motordriver 122 to operate pump motor 120 in a forward direction for salineflush and a reverse direction for waste aspiration. Optical encoder 124provides the Speed Direction Monitor signal to interface 102 whichindicates both the speed and the direction of rotation of pump motor120.

FIG. 3 illustrates an embodiment of the control system in which valvemotor 130 is used to actuate valves such as one-way valve 24 and thevalve within manifold 26. In this embodiment, computer 100 controlsvalve motor 130 through motor driver 132, and monitors position througha Position Monitor feedback signal from potentiometer 134. In thisparticular embodiment, valve, motor 130 is a stepper motor.

Computer 100 monitors temperature of the contrast material based upon aTemp Monitor signal from temperature sensor 140. Temperature sensor 140is preferably positioned near syringe body 18. If the temperature beingsensed by temperature sensor 140 is too high, computer 100 will disableoperation motor 104 to discontinue patient injection. If the temperatureis too low, computer 100 provides a /Temp Enable drive signal to heaterdrive 150, which energizes heater 152. In one preferred embodiment,heater 152 is a resistive film heater which is positioned within syringeholder 116 adjacent to syringe body 18.

Computer 100 also receives feedback signals from contrast bottle sensor160, forward limit sensor 162, reverse limit sensor 164, syringe missingsensor 166, chamber open sensor 168, no contrast bubble detector 170,and air in line bubble detector 172.

Contrast bottle sensor 160 is a miniature switch located withinreservoir holder 72. The state of the Contrast Bottle Present signalfrom sensor 160 indicates whether a reservoir 22 is in position withinholder 72. If reservoir 22 is not present, computer 100 will disable thefill operation.

Forward limit and reverse limit sensors 162 sense the end limitpositions of plunger 20. When plunger 20 reaches its forward limitposition, no further forward movement of plunger 20 is permitted.Similarly, when reverse limit sensor 164 indicates that plunger 20 hasreached its reverse limit position, no further reverse movements arepermitted.

Syringe missing sensor 166 is a miniature switch or infraredemitter/detector which indicates when syringe body 18 is not in positionwithin syringe holder 16. If syringe body 18 is not in position, allmovement functions are disabled except that plunger 20 can move to itsreverse limit position (i.e., return to zero).

Chamber open sensor 168 is a miniature switch or infraredemitter/detector which senses when door 70 of syringe holder 16 is open.When the signal from sensor 168 indicates that door 70 is open, allmovement functions are disabled. Only when door 70 is closed and lockedmay any movement be allowed. When door 70 is indicated as closed andsensor 166 indicates the syringe body 18 is in position, other normalfunctions of the system 10 can proceed.

Bubble detector 170 is positioned between reservoir 22 and top port 78,and is preferably an infrared emitter/detector which senses air bubbles.If an air bubble is sensed in the flow path between reservoir 22 and topport 78 during a fill operation, the fill operation is disabled until anew reservoir is connected.

Bubble detector 172 is positioned to sense air bubbles in high pressureline 28. It is preferably an infrared emitter/detector type of bubbledetector. Any air bubble which is sensed in high pressure line 28results in the disabling of all fluid push out functions, whether thefluid is saline solution from peristaltic pump 44 or contrast materialfrom syringe body 18.

The control system of FIG. 3 also includes the capability to provide acontrol signal to x-ray equipment through relay 180 which is controlledby computer 100. In addition, computer 100 receives data from bloodpressure transducer 38 and from an electrocardiograph (ECG) system whichis separate from injector system 10. The Pressure and ECG signals arereceived through signal conditioners and A/D converter 190, and aretransferred to computer 100. The ECG signal is used by computer 100 inone preferred embodiment, to synchronize operation of motor 104 (andthus the Patient Inject operation) with heart beats.

Blood flow to the heart occurs predominantly in diastole (when the heartis between contractions). Continuous injection of contrast materialresults in spillage of the contrast material into the aorta duringsystole (during contraction). By injecting primarily during diastole,contrast dosage can be reduced without impairing the completeness of thecontrast injection into the coronary artery.

In a preferred embodiment, the injection of radiographic contrastmaterial is synchronized to the coronary artery blood flow. The timeperiods of systole and diastole are determined using anelectrocardiographic (ECG) electrical signal, arterial blood pressurewaveform analysis, or other timing based on the heart rate. Bycontrolling speed of motor 104, speed and therefore movement of plunger20, the injection of contrast material is interrupted during the periodof systole, which reduces or stops contrast injection during this time.In combination with remote control 14, the operator can vary the rate ofcontrast injection into the coronary artery while computer 100automatically pulses the contrast injection to the cardiac cycle.

The inertial forces of the moving contrast material and expansion of thecontainers and tubing holding the contrast material and transmitting itto the patient can cause a phase lag between movement of plunger 20within syringe body 18 and movement of contrast material out of catheter30 into the patient. To adjust to the phase lag between the plunger 20movement and contrast expulsion into the patient, a variable time offsetcan be entered through control panel 54 such that the timing of thecardiac cycle can be offset by a selected time. Since the magnitude ofthe phase lag may be dependent on the frequency of the heart rate, analgorithm within computer 100 continuously and automatically adjusts themagnitude of the time offset, based on the instantaneous heart rateduring the injection of contrast material.

FIG. 4 shows one embodiment of control panel 54 which illustrates thefront panel control switches 56 and display 58 of one embodiment of thepresent invention Front panel control switches 56 include SetUp/Fill/End switch 200, Purge switch 202, Aspirate switch 204, Salineswitch 206, Enable OK switch 208, Injection Volume Limit switches 210 aand 210 b, Injection Flow Rate Limit switches 212 a and 212 b, InjectionPressure Limit switches 214 a and 214 b, Rise Time switches 216 a and216 b, OK switch 218, Injection Range Toggle switch 220, Large InjectionOK switch 222, and Stop switch 224.

Set Up/Fill/End switch 200 is a momentary, push button switch. When itis first activated, the user will be notified to place syringe 18 insyringe holder 16. When syringe 18 has been placed in syringe holder 16.(which is indicated to computer 100 by sensor 166), the user will beinstructed to close and lock the chamber (i.e., to close door 70).Plunger 20 is moved to its full forward position expelling all airwithin the syringe. Display 58 then indicates to the operator thatcontrast reservoir 22 should be connected. Once contrast reservoir 22has been put in place, the operator is requested to depress OK switch218, at which time plunger 20 will retract at a set rate (preferablycorresponding to a flow rate of 10 ml per second) to the maximum syringevolume. If the real speed (as indicated by feedback to, computer 100from A/D converter 116) is greater than the set speed, system 10 willstop.

Once plunger 20 is at its rearward most position, motor 104 is actuatedto move plunger 20 forward to purge all air bubbles. Pressure sensor 114provides an indication of when one-way valve 24 is closed and pressureis beginning to build up within syringe body 18. Once the purge iscompleted, the total volume injected and the number of injectionscounter is reset.

The actuation of switch 200 also allows for full retraction anddisengagement of plunger 20 from syringe body 18.

Purge switch 202 is a protected momentary push button switch. Whenactivated, Purge switch 202 causes plunger 20 to move forward to expelair through top port 78. The forward movement of plunger 20 is limitedand stopped when a predetermined pressure within syringe 18 is reached.This is sensed by pressure sensor 114. The purge operation which isinitiated by Purge switch 202 will expel air within syringe 20. The usermay also use Purge switch 202 to purge fluid through patient port 84 bydepressing and holding Purge switch 202 continuously on.

Aspirate switch 204 is a momentary push button switch which causescomputer 100 to activate pump motor 120 of peristaltic pump 44. Pumpmotor 120 is operated to aspirate catheter 30 at a set speed, with theaspirated fluid being collected in waste bag 52. All other motionfunctions are disengaged during aspiration If the real speed of motor.120 is greater than a set speed, computer 100 will stop motor 120.

Saline switch 206 is an alternate action switch Pump motor 120 isactivated in response to Saline switch 206 being pushed on, and salinesolution from bag 50 is introduced into manifold 26 and catheter 30 at aset speed If Saline switch 206 is not pushed a second time to stop theflow of saline solution within 10 seconds, computer 100 automaticallystops pump motor 120. If a time-out is reached, Saline switch 206 mustbe reset to its original state prior to initiating any further actions.

Enable OK switch 208 is a momentary push button switch. After the systemhas detected a disabling function at the end of an injection other thana limit, Enable OK switch 208 must be activated prior to activating OKswitch 218 and initiating any further function.

Injection Volume Limit keys 210 a and 210 b are pushed to eitherincrease or decrease the maximum injection volume that the system willinject during any one injection. Key 210 a causes an increase in themaximum volume value, and key 210 b causes a decrease. Once the maximuminjection volume limit has been set, if the measured volume reaches theset value, computer 100 will stop motor 104 and will not restart untilOK switch 213 has been depressed. If a large injection (i.e., greaterthan 10 ml) has been selected, OK switch 218 and Large Injection OKswitch 220 must both be reset prior to initiating the large injection.

Injection Flow Rate Limit keys 212 a and 212 b allow the physician toselect the maximum flow rate that the system can reach during any oneinjection. If the measured rate (which is determined by the feedbacksignals from tachometer 108 and potentiometer 111) reaches the setvalue, computer 100 will control motor 104 to limit the flow rate to theset value.

Injection Pressure Limit keys 214 a and 214 b allow the physician toselect the maximum pressure that the system can reach during any oneinjection. If the measured pressure, as determined by pressure sensor114, reaches the set value, computer 100 will control motor 104 to limitthe pressure to the injection pressure limit. The injection rate willalso be limited as a result.

Rise Time keys 216 a and 216 b allow the physician to select the risetime that the system will allow while changing flow rate during any oneinjection. Computer 100 controls motor 104 to limit the rise time to theset value.

In alternative embodiments, keys 210 a–210 b, 212 a–212 b, 214 a–214 b,and 216 a–216 b can be replaced by other devices for selecting numericalvalues. These include selector dials, numerical keypads, and touchscreens.

OK switch 218 is a momentary push button switch which resets functionsand hardware sensors. In response to OK switch 218 being activated,computer 100 controls display 58 to ask the operator to acknowledge thatthe correct function has been selected. Activation of OK switch 218causes the status to be set to Ready.

Injection Range switch 220 is a toggle switch Depending on whetherswitch 220 is in the “small” or “large” position, it selects either ahigh or a low injection volume range for the next injection.

Large Injection OK switch 222 is a momentary push button switch. Whenthe large injection range has been selected by injection range switch220, the Large Injection OK button 222 must be activated to enable OKswitch 218. OK switch 218 must be activated prior to each injection. Onlarge volume injections, the user is required to verify the volumeselected by activating first Large Injection OK switch 222 and then OKswitch 218.

Stop switch 224 is a momentary push button switch. When stop switch 224is pushed, it disables all functions. Display 58 remains active.

Display panel 58 includes Set-Up display 250, Status display 252, Alertsdisplay 254, Limits display 256, total number of injections display 260,total volume injection display 262, flow rate display 264, injectionvolume display 266, injection volume limit display 268, injection ratelimit display 270, pressure limit display 272, rise time minimum display274, large injection display 276, and real time clock display 278.

Set-Up display 250 contains a series of messages which are displayed asthe operator goes through the set up procedure. The display of messagesin set up display 250 are initiated by the actuation of set up switch200 as described previously.

Status display 252 provides a flashing indication of one of severaldifferent operating conditions. In the embodiment shown in FIG. 4, thesestatus conditions which can be displayed include “Ready”, “Set-Up”,“Injecting”, “Filling” “Flushing”, and “Aspirating”.

Alerts display 254 and Limits display 256 notify the operator ofconditions in which system 10 has encountered a critical controlparameter and will disable operation, or has reached an upper or lowerlimit and will continue to function in a limited fashion, or has reachedan upper or lower limit and will continue to operate.

Total number of injections display 260 displays the total number ofinjections (cumulative) given for the current patient case. Thecumulative total volume injected during the current patient case isdisplayed by total volume display 262.

Displays 264 and 266 provide information on the current or lastinjection. Display 264 shows digital value of the real time flow rate tothe patient during injection. Once the injection is completed, the valuedisplayed on display 264 represents the peak flow rate reached duringthat injection. Display 266 shows the digital value of the volumeinjected during the most recent injection.

Display 268 displays the digital value of the maximum injection volumeselected by operation of switches 210 a and 210 b. Similarly, display270 shows the digital value of the maximum flow rate that the systemwill allow, as selected by switches 212 a and 212 b.

Display 272 shows the digital value of the maximum pressure that thesystem will allow to be developed in syringe 18. The pressure limit isselected by switches 214 a and 214 b.

Display 274 displays the minimum rise time that the system will allowwhile changing flow rate. The minimum rise time is selected throughswitches 216 a and 216 b.

Large injection display 276 provides a clear indication when the largeinjection scale has been selected by the operator.

Real-time clock display 278 shows the current time in hours, minutes,and seconds.

FIGS. 5A and 5B show remote control 14 which includes main housing 300,which is designed to conform to the user's hand. Trigger 66 is movablewith respect to housing 300, and the position of trigger 66 generates acommand signal which is a function of trigger position. In oneembodiment, trigger 66 is linked to a potentiometer within housing 300.The command signal controls the injunction flow rate or speed. The flowrate is directly proportional to trigger position.

Reset switch 62 is a momentary push button switch whose function isidentical to that of OK switch 218. Alternatively, Reset switch 62 mayalso be labeled “OK”.

Saline switch 64 on remote control 14 is an alternate action push buttonswitch which is pushed to turn on and pushed again to turn off. Thefunction of Saline switch 62 is the same as that of Saline switch 206 onfront panel 54.

As illustrated in another embodiment of the present invention, analternative remote control 14′ in the form of a foot pedal is usedinstead of the hand held remote control 14 illustrated in FIG. 1 and inFIGS. 5A and 5B. Foot pedal remote control 14′ includes foot operatedspeed pedal or trigger 66′ for providing a command signal, as well asReset or OK switch 62′ and Saline switch 64′. Covers 310 and 312 protectswitches 62′ and 64′ so that they can only be actuated by hand and notaccidentally by foot. Foot pedal remote control 14′ is connected toconsole 12 by cable 60′, but could alternatively be connected by awireless link.

FIGS. 7A–7D and FIGS. 8A–8C illustrate the construction and operation ofone way valve 24 and manifold 26 during Contrast Fill, Air Purge andPatient Injection operation.

FIGS. 7A and 8A illustrate one way or check valve 24, manifold 26,syringe body 18, and plunger 20 during a Contrast Fill operation. Inletcheck valve of one way valve 24 includes weighted ball 350 which ispositioned at its lower seated position within valve chamber 352 inFIGS. 7A and 7B. Contrast material is being drawn into syringe body 18by the rearward movement of plunger 20. The contrast material flowsthrough passages 354 around ball 350 and into upper port 78.

Manifold 26 contains spring loaded spool valve 360, which includes spoolbody 362, shaft 364, O-rings 366, 368 and 370, bias spring 372, andretainer 374. As shown in FIG. 7A, during the Contrast Fill operation,bias spring 372 urges spool body 362 to its right-most position towardsyringe body 18. In this position, spool body 362 blocks lower port 80of syringe body 18 while connecting transducer saline port 82 to patientport 84 through diagonal passage 376. O-rings 366 and 368 on the onehand, and O-ring 370 on the other hand, are positioned on the oppositesides of diagonal passage 376 to provide a fluid seal.

FIGS. 7B and 8B illustrate the Air Purge operation. Syringe body 18 hasbeen filled with contrast fluid, but also contains trapped air. Plunger20 is driven forward to force the air out of syringe body 18 throughupper port 78 and through check valve 24. The force of the air may causea slight lifting of ball 350 in check valve 20. Ball 350, however, issufficiently heavy that the air being forced out of syringe body 18 andback toward reservoir 22 cannot lift ball 350 into its uppermost seatedposition where it would block the flow of air out of syringe body 18.

During the Air Puree operation, spool valve 360 is in the same positionas in FIG. 7A. Diagonal passage 376 connects transducer saline port 82with patient port 84. As a result, pressure monitoring by pressuretransducer 38 can be performed during the Air Purge (as well as theContrast Fill) operation.

FIGS. 7C and 8C illustrate the state of manifold 26 and check valve 24at the end of the Air Purge operation and at the beginning of a PatientInject operation.

In FIG. 7C, all air has been expelled from syringe body 18. Ball 350floats on the radiographic contrast material, so that when all air hasbeen removed and the radiographic contrast material begins to flow outof syringe body 18 and through upper port 78 to valve chamber 352, ball350 is moved upwards to its upper seated position. Ball 350 blocks anycontinued upward flow of radiographic contrast material, as isillustrated in FIGS. 7C and 8C.

In the state which is illustrated in FIG. 7C, the pressure withinsyringe body 18, and specifically the pressure in lower port 80 has notyet reached a level at which the bias force of spring 372 has beenovercome. As a result, spool body 362 has not yet moved to the left anddiagonal passage 376 continues to connect transducer saline port 82 withpatient port 84.

FIG. 7D illustrates the patient inject operation. Plunger 20 is movingforward, and inlet check valve 24 is closed. The pressure at lower port80 has become sufficiently high to overcome the bias force of spring372. Spool body 362 has been driven to the left so that lower port 80 isconnected to patient port 84. At the same time spool body 362 blockstransducer/saline port 82.

By virtue of the operation of spool valve 360, the high pressuregenerated by movement of plunger 20 and syringe body 18 is directlyconnected to patient port 84, while saline port 82 and pressuretransducer 38 are protected from the high pressure. The pressure toactuate may be variable and determined after manufacture by increasingor decreasing the syringe preload.

FIGS. 9–11B illustrate another embodiment of the dual port syringe inthe present invention. In this embodiment, conventional syringe body 400is modified to provide dual port functionality. The modification isaccomplished by adapter insert 402 and T-connector 404.

Syringe body 400 has a cylindrical side wall 410 frustoconical end wall412, and tubular end port 414. Adapter insert 402, which is shown inmore detail in FIGS. 10 and 11 is inserted into syringe body 400 so thatit mates with end wall 412 and tube 414. T-connector 404 connects to theend of tube 414, and provides upper port 420 and lower port 422.

Adapter insert 402 has a frustoconical flange 430 and a generallycylindrical shaft 432. Flange 430 mates against the inner surface of endwall 412 of syringe body 400. Shaft 432 extends through tube 414 andthrough T-connector 404, so that end surface 434 of shaft 432 isgenerally located at the distal end of T-connector 404. Upper portgroove 436 extends along the upper surface of shaft 432 and the inclinedupper surface of flange 430. Upper port groove 436 stops just short ofend 434.

Lower port groove 438 extends the entire length of shaft 432, along itslower surface, and then extends downward on the inclined lower surfaceflange 430.

When adapter insert 402 is positioned within syringe body 400 as shownin FIG. 9, it forms a close press fit with both syringe body 400 andT-connector 404. Upper port groove 436 provides an upper port passagewhich extends from port 420 to the interior of syringe body 400. Asshown in FIG. 9, upper port groove 436 opens into the interior ofsyringe body 400 at the uppermost portion of the interior.

Lower port groove 438 extends from the distal end of T-connector 404 tothe lowermost position in the interior of syringe body 400.

The embodiment of the present invention shown in FIGS. 9–11B provides aninexpensive adaptation of a conventional syringe body so that it canexhibit the advantages of dual port capability.

In conclusion, the angiographic injector system of the present inventionprovides interactive control of the delivery of radiographic contrastmaterial to a catheter through a user-actuated proportional control.This allows the user to adjust the flow rate of contrast materialinteractively as needed and as the patients condition changes.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. For example, syringe holder 16 may takeother forms, such as an end loaded cylinder. Similarly, manifold 26 cantake other configurations and can incorporate, for example, a part ofports 78 and 80.

B. Detailed Description of the Present Invention

FIGS. 12–17 depict one preferred syringe 500 usable in the angiographicsystem described above. Syringe 500 includes a syringe body 502 having awall defining first and second opposite ends 504, 506. The first end 504corresponds to a distal end of syringe 500, and the second end 506corresponds to a proximal end of syringe 500. The wall of body 502 iscylindrical in the illustrated embodiment and includes a central axis508 extending longitudinally therethrough.

Syringe body 502 defines a pumping chamber 510 in an interior thereof. Awiper or plunger 512 is located in the pumping chamber 510 and isconstructed and arranged for reciprocal motion between a positionadjacent to first end 504 and second end 506. That is, when syringe 500is mounted in a system analogous to the angiographic system describedherein above, an actuator from the system energizes the plunger andcauses it to move between the second end 506 and the first end 504. Theplunger 512 is supported by a plunger support member 617. Member 617preferably comprises a rigid, hard material, for example, an ABSplastic, to interface between an actuator and the plunger 512. Member617 attaches to plunger 512 by, preferably, a snap fit.

Syringe 500 includes an end wall 514 located at the first end 504 of thesyringe body 502. End wall 514 is located generally normal to thecentral, longitudinal axis 508 of syringe 500. The end wall 514 includesa flat face 516. The flat face 516 is particularly adapted for matingengagement with a syringe holder, to be described further below, in anangiographic system as described above. Flat face 516 is advantageous inthe preferred arrangement. In the angiographic system as describedherein, significant thrust loads must be borne in order to suitablyinject the contrast material into the cardiovascular system of thepatient. Flat face 516 allows the thrust load from the injections to bedistributed in a manageable fashion. An angled face, in contrast, wouldcreate a wedge action, which would unnecessarily stress the syringe andcreate an unnecessary side load in the syringe holder. The inventorshave recognized that a spherical or cone face would require a large doorin the syringe holder to support the thrust and would also require someelaborate mechanism to properly position the door against the syringe.Flat face 516 on syringe 500, however, allows the thrust load to bemanaged by a thin flat door, to be described in more detail below, andis able to bear the thrust load from the angiographic injections.

Syringe 500 defines at least one port for providing fluid flowcommunication with pumping chamber 510. In the particular embodimentillustrated, syringe 500 includes two ports providing fluid flowcommunication with the pumping chamber 510. Specifically, an inlet port518, FIG. 14, allows the pumping chamber 510 in syringe 500 to be filledwith contrast material, and purged or air through inlet port 518,allowing for an infinite capacity syringe. By “infinite capacity” it ismeant that syringe 500 continues to take in contrast media from a bottleof contrast media; the bottles being replaced when empty. A housing 520circumscribes inlet port 518 and allows inlet port 518 to be connectedwith an appropriate bottle 602 of contrast fluid. When syringe 500 isoriented in a syringe holder in an angiographic system as describedabove syringe 500 defines a top portion and a bottom portion. FIG. 15illustrates the orientation of syringe 500 as it would be mounted in anangiographic system of the preferred embodiment. When in such anorientation, the inlet port 518 is located in the top portion 522 ofsyringe 500.

In preferred embodiments, the syringe 500 is mounted in an angiographicsystem such that the syringe 500 angles somewhat from the horizontal. Byangling the syringe 500 from the horizontal, air is allowed to gatheraround the inlet port 518 in order to be expelled through the inlet port518 during an air purge operation. Angles within the range of about5–30°, and preferably about 10–15° from the horizontal are preferable.

Inlet housing 520 houses a valve assembly analogous to check valve 24,described and illustrated above. Check valve 24 is competent to fluid,and incompetent to air. That is, check valve 24 permits air to beexpelled or purged from the syringe 500, but does not allow fluid toflow out of the pumping chamber 510 and back into the bottle 602 ofcontrast fluid when pressure movement is applied on the syringe side ofthe check valve 24.

Syringe 500 also includes an outlet port 524, FIG. 16, in fluid flowcommunication with pumping chamber 510. Outlet port 524 permits fluidflow from pumping chamber 510 to downstream fluid passageways, andultimately into the patient's cardiovascular system. Outlet port 524 issurrounded, or circumscribed, by outlet port housing 526 extending, orprojecting, from end wall 514. The outlet port housing 526 is adapted,i.e., constructed and arranged, to receive an outlet tube. Outlet port524 and outlet housing 526 are analogous to lower port 80, described indetail above.

When syringe 500 is oriented in the preferred angiographic system of thepresent invention, the outlet port 524 is located adjacent to the bottomportion 523 of syringe 500.

The syringe end wall 514 includes an interior portion 528, FIG. 17, andan exterior portion 530, FIG. 14. It is the exterior portion 530 whichdefines the flat face 516 of syringe 500. The exterior portion 530includes a plurality of ribs 532. In the embodiment illustrated, thereare seven ribs 532 extending transversely across the end wall 514. Ribs532 help to provide a reinforcing function. Ribs 532 also provide anattractive, ornamental appearance to syringe 500.

Ribs 532 each have end portions 534 terminating in a plane transverse tolongitudinal axis 508 of syringe body 502. The end portions 534 definethe flat face 516.

The interior portion 528 defines a cone-shaped surface 536, FIG. 17.This cone-shaped surface 536 is illustrated in FIG. 17 by the shadingtherein. Cone-shaped surface 536 helps to direct the liquid in pumpingchamber 510 to an appropriate fluid port.

Preferred dimensions for syringe 500 are described herein below. Syringebody 502 has a diameter of about 1.3 inches. The length of syringe body502 between first end 504 and second end 506 is about 6–7 inches. Theinside of syringe body 502 is tapered so that second end 506 has aninside diameter greater than the inside diameter of interior portion 528of the end wall 514. This taper is about 0.1° from horizontal for themajority of its length. The angle of tapering increases to about 1° at apoint about 1 inch from the second end 506 of syringe 500. The interiorportion 528 defining the cone-shaped surface 536 slopes at an angle ofabout 27° from vertical, and the vertex of the cone is rounded at aradius of about 0.25 inches. Each of ribs 532 is about 0.1 inches thick.The ribs 532 are spaced about 0.12 inches apart; The outlet port housing526 has an outer diameter of about 0.3 inches, and an inner diameter ofabout 0.2 inches. The longitudinal axis of the outlet port housing 526is parallel to and about 0.5 inches lower than the central longitudinalaxis 508 of syringe body 502. The outlet port housing 526 is arrangedrelative to the syringe body 502, such that the outer diameter of theoutlet port housing 526 intersects at a tangent point of the diameter ofsyringe body 502. The inlet port housing 520 has an outer diameter ofabout 0.4 inches and an inside diameter of about 0.2 inches. Thelongitudinal axis of the inlet port housing 520 is tilted about 10° fromvertical toward the end wall 514. The inlet port 518 has a diameter ofabout 0.1 inches. The inlet port housing 520 is about 0.5 inches longmeasured from where the inlet housing 520 meets the syringe body 502 inthe top portion 522 of the syringe 500.

In reference now to FIGS. 18–20, a syringe holder arrangement isillustrated generally at 540.

In general, the syringe holder arrangement 540 includes a mountingchamber body 542; a door member 544; a rear plate 546; and a pressurecontainment sleeve 548. Preferred assemblies further include a bottleholder assembly 550; an air column detector 552; and a manifold holder554.

Mounting chamber body 542 is for holding the syringe in place during anangiographic operation. The mounting chamber body 542 is constructed andarranged to be durable enough to sustain large pressure loads from thefluid push through syringe 500. Mounting chamber body 542 has an arcuateconfiguration for receipt of sleeve 548. It includes a loading end 556for receipt of syringe 500, and an actuating end 558 for receiving theactuator to reciprocate the syringe plunger 512 between its respectiveproximal and distal positions within syringe 500. The loading end 556also corresponds to the front of the mounting chamber body 542, and theactuating end 558 corresponds to the back or rear of the mountingchamber body 542.

Preferably, the mounting chamber body 542 comprises a series of layersin order to provide a convenient and preferred structure for holdingsyringe 500. In particular, the outermost layer is anelectroilluminescent layer. The electroilluminescent layer permitsillumination of the mounting chamber body 542 and the associated tubing.That is, the electroluminescent layer illuminates the fluid pathway ofthe contrast material as it is being conveyed from the syringe 500 todownstream components and ultimately into the patient's cardiovascularsystem.

Adjacent to the electroilluminescent layer is a membrane heatingelement. This layer maintains heat of the contrast fluid in order tosustain a desired viscosity in the contrast fluid for conveying into thepatient's cardiovascular system.

The next layer of the mounting chamber body 542 and adjacent to themembrane heating element layer is a layer of foam. The foam layer keepscontact resistance with the syringe 500 high and thermal resistance low.It functions to take up tolerances and helps to snugly hold the syringe500 in place in the syringe holder arrangement 540.

The last layer of the mounting chamber body 542 is an aluminumextrusion. It provides for a rigid shape and for convenientmanufacturing. A layer of adhesive attaches the foam layer to thealuminum extrusion.

As illustrated in FIG. 20, the mounting chamber body 542 includes a pairof back flanges 559, 560 defining a groove 561 therebetween The groove561 provides for storage and containment of wires to the syringe holderarrangement 540. A plate 562 slides in groove 561 and is securablyattached thereto to provide for neat and convenient storage.

Still referring to FIG. 18, door member 544 is provided to allow forselective opening and closing of the loading end 556 of body 542. Thatis, door member 544 is movable relative to mounting chamber body 542between positions allowing access to mounting chamber body 542, and intothe interior of sleeve 548, and a position which blocks, or closesaccess to, the interior of sleeve 548. In the position where it closesaccess, door 544 provides for a stop surface to support and resist theload applied through the syringe 500 when the plunger is depressed.

In the particular embodiment illustrated, the door member 544 ispivotable relative to the mounting chamber body 542. This allows forquick and convenient loading and unloading of syringe 500 into theholding arrangement 540. When the door 544 is in its closed position,FIG. 19, it locks the syringe 500 into place in the holder arrangement540.

In reference again to FIG. 18 and FIG. 20, door member 544 is astructure with a pair of flat, planar, opposite surfaces 563, 564.Preferably, it is an a fabricated stainless steel plate with a thicknessof about 0.4–1 inches. Flat surface 564, FIG. 20, is constructed andarranged for a sliding, abutting engagement with the flat end wall 514of syringe 500 and pressure sleeve 548. It also slides relative to andabuts against the end surface of sleeve 548. Because of the geometry ofthe flat face 516 of the end wall 514 of syringe 500, the thrust loadexerted by the angiographic system 10 through syringe 500 can be managedby the flat door member 544.

In reference again to FIG. 18, door member 544 defines a channel,groove, or slot 565. Slot 565 is an open, through-hole penetrating doormember 544 and extending to the edge of door member 544. Slot 565provides for slidable communication with outlet port housing 526 ofsyringe 500. That is, when syringe 500 is oriented properly for loadingin holding arrangement 540, after syringe 500 is resting within sleeve548, as door member 544 is pivoted to the closed position, FIG. 19,outlet port housing 526 slides within groove 565. Groove 565 permits theoutlet port housing 526 to extend and penetrate through door member 544to permit liquid from syringe 500 to be conveyed to downstreamcomponents.

Still referring to FIG. 18, door member 544 includes a handle 566.Handle 566 extends from a side edge of door member 544 and allows for auser to conveniently pivot the door member 544 between its closedposition and its open positions. Door member 544 pivots about its lowestpoint preventing door member 544 from acting as a guillotine when actedupon by gravity. That is, the arrangement of the door member 544relative to its pivot point prevents injury to fingers.

In accordance with the invention, a door open sensor is provided. Thedoor open sensor tells the user or operator if the door member 544 is inan open position. That is, it functions as a safety feature such thatthe angiographic system 10 will not be operated if door member 544 isnot in a securely closed position. In the particular embodimentillustrated, the door open sensor includes a magnet 567 in the doormember 544, and a Hall effect sensor in the mounting chamber body 542.When door member 544 is pivoted to its closed position, FIG. 19, magnet567 is in contact with mounting chamber body 542. The Hall effect sensorsenses the presence of magnet 567 and provides an indication to theoperator that the door member 544 is closed. When the Hall effect sensordoes not sense the presence of magnet 567, it provides a signal to theoperator that the door member 544 is not in the closed position, but inan open position. One suitable sensor is Hall effect sensor 55449A,available from Microswitch (a division of Honeywell).

Still referring to FIG. 18, the pressure containment sleeve 548 isprovided in the holding arrangement 540 to hold syringe 500 snuglybetween door member 544 and rear plate 546. Sleeve 548 helps to containthe pressure exerted through the syringe 500, and allows for largepressure forces through the syringe 500. The close fit between rearplate 546 and door member 544 holds the syringe 500 so that noforward/rearward movement is allowed.

In the particular embodiment illustrated, sleeve 548 is constructed andarranged to fit, or slide in the mounting chamber body 542. In thepreferred embodiment, sleeve 548 is cylindrical, or tubular in shapewith first and second open ends 568, 569 (FIG. 20). Sleeve 548 ispreferably constructed from a strong, durable, basically transparentmaterial in order to sustain large pressure loads and allow forvisibility of the syringe therethrough. One preferred material includespolycarbonate.

In reference to FIG. 19, the first end 568 of sleeve 548 is open andallows the outlet port housing 526 to project, or extend therefrom andthrough slot 565 in door member 544. Second end 569, FIG. 20, permits anactuator from angiographic system 10 to penetrate sleeve 548 and accessthe syringe plunger support member 617.

Referring again to FIGS. 18 and 19, it can be seen that door member 544slides relative to the first end 568 of the sleeve 548, as door member544 is moved between its closed position and open positions.

Sleeve 548 defines an open groove, or channel 570 extending from thefirst end 568. Channel 570 accommodates a sensor 571. Sensor 571 isoriented relative to the valve assembly in the inlet housing 520 inorder to detect the state of the check valve. That is, sensor 571detects whether the ball in the check valve is seated in its lowermostposition or whether it has been moved out of its lowermost position. Inthe particular arrangement illustrated, the sensor 571 is anemitter/detector interruptable infrared photodetector device. When theball interrupts the infrared beam, a signal is sent indicating that theball is seated in its lowermost position or seat When the ball is movedout of its lowermost position or seat, the infrared beam is notinterrupted, and a signal is generated which indicates that the ball isout of its lower seat.

A connector 690 and wire 692 energize the sensor 571. That is, connector690 connects the electrical components and wires within groove 691 tothe sensor 571.

As can be seen in FIGS. 18 and 20, sensor 571 is generally U-shaped. TheU-shape, in addition to enabling detecting of the ball in the checkvalve, also allows the inlet port housing 520 to be accommodated withinsleeve 548 in holding arrangement 540. As illustrated in FIG. 19, whensyringe 500 is loaded into holding arrangement 540, it is slid throughsleeve 548, and sensor 571 permits inlet port housing 520 to rest withinthe U-shape of the sensor 571 and extend radially from sleeve 548. Inthis way, fluid communication is permitted from the source of contrastfluid and into syringe 500, even after syringe 500 is loaded within theholding arrangement 540. One type of sensor 571 useable is an infrareddiode (part number SE-1450-004L) and photo-transistor pair (part numberSD-1440-004L), both available from Microswitch (a division ofHoneywell).

In the preferred embodiment, the sleeve 548 is conveniently removablefrom the mounting chamber body 542. In this manner, it may be cleanedand disinfected separate from the chamber body 542. In the particularembodiment illustrated in FIG. 20, sleeve 548 is slidable relative tomounting chamber body 542 and can be lockably secured thereto throughthe cooperation of a locking pin 572 and a locking assembly 574 in therear plate 546. Locking pin 572 extends from second end 569 of sleeve548. Locking assembly 574 is a spring loaded locking member that engagesand holds pin 572.

Again, in reference to FIG. 18, the rear plate 546 is secured to themounting chamber body 542 and is in covering relation to the second end569 of the sleeve 548. Rear plate 546 supports the actuating end 558 ofthe mounting chamber body 542.

In the particular embodiment illustrated, rear plate 546 has arectangular configuration. Preferably, it is an aluminum fabricatedplate, with a thickness of about 0.6 inches.

In reference now to FIG. 20, rear plate 546 defines an aperture 576 in acentral portion therethrough. Aperture 576 allows access to the interiorof sleeve 548. That is, aperture 576 permits the angiographic actuatorto penetrate and move the syringe plunger 512 between its respectiveproximal ends and distal ends of syringe 500.

In reference now to FIGS. 18 and 19, the bottle holder assembly 550 isprovided to hold a bottle 602 of contrast fluid in order to quickly andconveniently provide a constant source of contrast media to the syringe500 when it is loaded in holding assembly 540.

In the illustrated embodiment, bottle holder assembly 550 is secured tomounting chamber body 542. Bottle holder assembly 550 includes a column578 and a neck portion 580.

Neck portion 580 is pivotable with respect to mounting chamber body 542in the direction of arrow 581. The pivotable nature of neck portion 580aids the ease of connecting the tubing from the bottle 602 of contrastmedia to the inlet housing 520 of the syringe 500.

Neck 580 includes universal detail 584 within grooves 586. Universaldetail 584 is preferably a spring loaded configured member which allowsbottle holder 550 to accommodate and hold bottles of various sizes.

In accordance with the invention, an indicator arrangement is providedto provide information whether a bottle is in the bottle holder assembly550. In the preferred embodiment, a switch is provided in the universaldetail 584. When a bottle 602 of contrast is within the neck 580, thebottle 602 presses against the spring in the universal detail 584, whichactuates the switch. When the switch is actuated, it provides a visualsignal to the system operator that a bottle is in fact in the bottleholder assembly 550. If the switch is not actuated, a signal is providedto the user that there is no bottle in the holder assembly 550. Onesuitable switch is a microswitch MMGGDILOO, available from C&K.

In accordance with the invention, a sensor is provided to indicate ifthe fluid level in the bottle 602 of contrast is either below a certainlevel or empty. Preferably, the sensor includes a sensor provided withingroove 586 in neck 580. The sensor detects when the fluid level in thebottle 602 has dropped below the level of the sensor in the neck 580.Preferably, the sensor is a reflective, infrared device. One type ofsensor useable is infrared sensor H0A1405-2, available from Microswitch(a division of Honeywell).

In reference again to FIGS. 18 and 19, air column detector 552 isprovided to detect the presence of air in the fluid line 588 (FIG. 19).Air column detector 552 is analogous to air bubble detector 172,described above. It uses ultrasonic means to detect the presence of airin the line 588. One suitable ultrasonic means is available fromIntrotek of New York.

Air column detector 552 defines a groove 590, FIG. 18, which provides afriction fit with fluid line 588. That is, the tubing snaps into groove590 where it is securely held therein. Holders 627, 628 swing down overfluid line 588 to secure it in place (FIG. 19). A flange 592 providesfor attachment of the air column detector 552 to the mounting chamberbody 552.

In reference now to FIG. 22, air column detector 552 is shown engagingfluid line 588 which has been wrapped around itself to form a loop 651.Although no particular theory with respect to this arrangement isasserted hereto, it is believed that by forming a loop 651 in fluid line588, any air bubbles present within the fluid line 588 will be at a topside of the tube due to buoyancy resulting from gravitational forces andcentrifugal forces due to the fluid flow. Gravitational forces push thebubble to the top side of the tube 588. Centrifugal forces push thebubble to the inside of the bend radius of the loop 651. By the sectionbeing at the bottom quadrant, both of these forces will be in the samedirection pushing the bubble to the inside of the bend of the loop 651and the top of the tube 588, independent of bend radius or fluidvelocity. Thus, the bubble is forced to the top side of the tube 588. Incertain arrangements, this tends to enhance the detection of any airbubbles by air column detector 552.

Again in reference to FIGS. 18 and 19, manifold holder 554 is providedto secure and hold a manifold, analogous to manifold 26, describedabove. A clamp structure 597 holds the manifold securely in place.Manifold holder 554 is mounted on a flange 594, which is secured tomounting chamber body 542. Manifold holder 554 is mounted on flange 594in a slot 596, FIG. 20, to permit manifold holder 554 to slide back andforth within groove 596. This permits manifold holder 554 to accommodatedifferent lengths of tubing 598, FIG. 19, from the outlet port housing526 of the syringe 500.

Manifold holder 554 is configured and shaped to permit the manifold tosnap in only one orientation. In this way, it can be assured that themanifold is always oriented in the same position relative to themanifold holder 554. Because of this, a sensor 599 can detect theposition of the valve within the manifold. The sensor 599 is positionedin an integral part with the manifold 554. Sensor 599 preferably is aninductive type device. One type of sensor useable in the embodimentshown is an inductive sensor (part number IFRM 12P1701\L) available fromBaumer.

Attention is again directed to FIG. 20. In FIG. 20, a pair of volumeindicators 606, 607 are illustrated. Volume indicators 606, 607 areoriented relative to mounting chamber body 542, such that when syringe500 is situated within mounting chamber body 542, the volume indicators606, 607 provide a visual cue and indication for the level of fluidwithin the syringe body 502. As shown in FIG. 20, volume indicators:606, 607 each include a plurality of marks 608. As the fluid levelwithin syringe body 502 changes, the user is able to visually detectwhere the level is by comparing it against the marks 608.

In accordance with the invention, a method for mounting or loading asyringe is provided. The method includes a step of positioning a syringethrough a front aperture in a syringe holder arrangement. This includessliding a syringe, such as syringe 500 in through the front end of asyringe holder arrangement 540. Using the components illustrated in thedrawings, the syringe 500 is oriented to line up with the open end ofthe first end of the sleeve 543. That is, the second end 506 of thesyringe 500 is aligned with the front of the sleeve 548, and the inletport housing 570 is aligned with the slot 570. The rear, or second end506, of syringe 500 (that is, the plunger receiving end) is first slidthrough the open end defined by the first end 568 of the sleeve 548.This is followed by the fluid-dispersement end of the sleeve, i.e., thefirst end 504 defining the flat face 516. The syringe 500 is slid intothe interior of the sleeve 548.

Next, the door is closed. This blocks further access to the interior ofthe sleeve 548. This also provides for a stop surface, engagementsurface, or abutting surface for the syringe 500 in order to absorb andsustain pressure load through the syringe 500. Specifically, the doormember 564 is pivoted from one of its open positions, FIG. 18, to itsclosed position, FIG. 19. The user grasps the handle 566 and pivots thedoor to close the opening. As the door member 544 is being pivoted, theflat surface 564 of the door is slid relative to the flat face, 516, ofthe syringe 500, and relative to the first end portion 568 of the sleeve548. As the door member 544 is moved into its closed position, theoutlet tube housing 526 communicates with and slides through groove 565.

To unload the syringe 500 from the syringe holder arrangement 540, theabove process is basically done in reverse. The door member 544 ispivoted from its closed position, FIG. 19, into one of its openpositions, such as that illustrated in FIG. 18. The syringe 500 is thenremoved from the holder assembly 540. Specifically, the syringe 500 isslid from the interior of sleeve 548. The front end of syringe 500, thatis, the end with the flat face 516, is slid out first, followed by therear end, or second end 506.

In accordance with the invention, the angiographic system describedherein is constructed and arranged to ensure that syringe 500 is notre-used. That is, the angiographic system of the present inventionincludes features to ensure that the syringe 500 is disposed of afteruse with one patient and not accidentally re-used on a new, differentpatient As embodied herein, the syringe 500 includes structure on itsplunger support member 617 to ensure single use. As illustrated in FIG.21, plunger support member 617 defines a plurality of projections ortabs 610. Tabs 610 project or extend radially inwardly toward the centeror apex of the plunger 512. Tabs 610 are constructed of a flexible,deformable material, but also frangible or breakable, such that when theactuator engages plunger support member 617, tabs 610 are bent inwardlyto accommodate the actuator. However, when syringe 500 is removed fromthe actuator, tabs 610 are broken, and the plunger support member 617 isdestroyed. This prevents the syringe 500 from being re-used.

After a period of use, it may be desirable to remove the pressurecontainment sleeve 548 for cleaning. To do this, the locking assembly574 in the rear plate 546 is shifted to disengage and release thelocking pin 572. While the locking pin 572 is disengaged from thelocking assembly 574, the sleeve 548 may be grasped at a first end 568and slid out from its snug engagement with the mounting chamber body542. At this point, the sleeve 548 may be cleaned.

To reinsert the sleeve 548, the sleeve 548 is slid back into secure,snug engagement with the mounting chamber 542. The locking assembly 574is shifted to permit locking engagement with the locking pin 572.

1. A method for using a syringe in an injector system, the methodcomprising: providing a syringe that includes a pumping chamber and aplunger; inserting an actuator into the plunger; and irreversiblydeforming the plunger to preclude further use by removing the actuatorfrom the plunger, wherein the plunger comprises a plurality of tabs thatextend inward towards a center of the plunger, wherein the tabs are bentto accommodate the actuator when the plunger is engaged by the actuatorduring insertion, and wherein the tabs are broken when the actuator isremoved from the plunger.
 2. The method of claim 1, wherein the tabs areconstructed of a flexible, deformable material.
 3. The method of claim1, wherein the plunger, after being deformed, cannot engage theactuator.
 4. The method of claim 1, wherein the actuator is removed fromthe plunger after the syringe has been used on one patient and before itis used on another patient.
 5. The method of claim 1, wherein theinjector system comprises a motorized injection system.
 6. The method ofclaim 1, wherein the plunger comprises a plunger support member thatincludes the plurality of tabs.